Gravitational form factors and angular momentum densities in light-front quark-diquark model

TL;DR

This paper explores gravitational form factors and angular momentum densities in a light-front quark-diquark model of the proton, using AdS/QCD predictions and comparing with GPD parametrizations and experimental data.

Contribution

It introduces a light-front quark-diquark model incorporating scalar and axial vector diquarks based on AdS/QCD, providing new insights into proton GFFs and angular momentum distributions.

Findings

Calculated gravitational form factors consistent with GPD parametrizations.

Mapped spatial angular momentum distributions for up and down quarks.

Compared model results with recent experimental measurements.

Abstract

We investigate the gravitational form factors (GFFs) and the longitudinal momentum densities ($p^+$ densities) for proton in a light-front quark-diquark model. The light-front wave functions are constructed from the soft-wall AdS/QCD prediction. The contributions from both the scalar and the axial vector diquarks are considered here. The results are compared with the consequences of a parametrization of nucleon generalized parton distributions (GPDs) in the light of recent MRST measurements of parton distribution functions (PDFs) and a soft-wall AdS/QCD model. The spatial distribution of angular momentum for up and down quarks inside the nucleon has been presented. At the density level, we illustrate different definitions of angular momentum explicitly for an up and down quark in the light-front quark-diquark model inspired by AdS/QCD.